Tool & Cutter Grinder Product

Overview

A tool and cutter grinder sharpens the tools every other machine in the shop consumes: end mills, drills, reamers, taps, milling cutters, hobs, and single-point tooling. A dull 20 mm end mill costs a fraction of a new one to regrind, and the regrind restores the precise clearance and rake angles that determine how the tool cuts. The machine is built around reach and angular freedom rather than power — its Spindle Motor is only about 1.1 kW — because the job is removing hundredths of a millimetre from hardened steel and carbide edges at exactly controlled angles.

The classic manual architecture (Cincinnati No. 2, Deckel S0/S1, and their many descendants) has three interacting groups: a Universal Workhead that can hold a tool in nearly any orientation, a Wheelhead that swings and elevates on the Column, and free-moving Table Axes the operator strokes by hand. CNC tool grinders have taken over production regrinding, but the manual universal remains standard for toolroom work, form tools, and odd geometries.

Geometry: how angles are generated

Everything on this machine reduces to one principle: a cutting edge is ground to a clearance angle by offsetting the contact point between wheel and edge. The tool is supported on a Tooth Rest — a thin spring-steel finger set against the face of the tooth being ground. Raising or lowering the wheel relative to the rest by a calculated amount (offset = wheel radius × sin of the clearance angle, for a cup wheel about 0.17 mm per degree at typical sizes) tilts the ground flank to the required 5-12 degrees of primary clearance. The operator grinds one tooth, indexes the Workhead Spindle to the next via the 24-notch Index Ring, and repeats around the tool.

Helical flutes complicate this: as the table traverses, the edge twists. The fix is elegant — the tooth rest is fixed to the wheelhead, not the table, and the tool is held in the frictionless Air Bearing Spindle. As the operator draws the end mill past the wheel on the Traverse Table, the flute riding the rest finger rotates the tool automatically, keeping the edge at constant height and the clearance constant along the whole helix.

The Universal Workhead supplies the remaining freedoms: the Workhead Swivel Base and Workhead Tilt Joint are graduated in degrees for compound angles such as end-tooth gashes and dish angles, and tools clamp in the Collet Set or, for bore-type cutters, on the Arbor Set between the Tailstock Pair centers. Dedicated attachments handle recurring jobs: the Drill Point Fixture generates conical or four-facet drill points, and the Radius Fixture sweeps ball-nose and corner radii about a set pivot.

Wheels

The Grinding Spindle is double-ended, so two wheel shapes are mounted at once, and wheels live on balanced Quick-Change Wheel Hub quick-change hubs that preserve truth between swaps. Shape follows task: the flat face of a Cup Wheel grinds primary and secondary clearances flat; the thin Dish Wheel reaches into flutes and gashes; the Plain Wheel handles cylindrical work. Abrasive follows tool material — vitrified aluminium oxide (typically 46-60 grit, J-K grade) for high-speed steel, and the resin-bond Diamond Cup Wheel for tungsten carbide, which aluminium oxide barely scratches. Wheels run at 3,000 or 6,000 rpm by the Speed Selector Switch to keep surface speed near 20-25 m/s across diameters, and are conditioned with a Dressing Stick.

Operation and dust

Work is done dry and by feel. The Cross Handwheel sets infeed in 0.005 mm divisions — a typical regrind removes 0.05-0.15 mm per flank in two or three passes — while the roller-mounted traverse table floats freely so the operator senses wheel contact through the handles, stroking between Table Stop dogs. Sparks tell the story: a continuous even spark line along the stroke means the edge is straight and the rest is set right.

Dry grinding makes the Dust Extraction system a health requirement, not a convenience. Carbide swarf carries cobalt, with a workplace exposure limit of 0.02 mg/m³; the Capture Hood pulls the spark stream into a Cyclone Separator and an H13 HEPA Filter Cartridge, with collected carbide saved in the Dust Drawer for reclaim — tungsten scrap has real salvage value. The machine's accuracy outlives most shops: a well-kept universal from the 1960s still splits half-thousandths, because everything it does is geometry, springs, and a small motor.